FORGET ever increasing milk yields, better use of sexed semen from proven pure and cross-bred dairy and beef sires is paying real dividends down under in New Zealand, where average yields are just shy of five lactations.

That was the take home message from Tim Bunnett, sales operations manager with the NZ Livestock Improvement Cooperation (LIC), a multi-national farmer owned co-operative which provides genetics expertise, information and technology to the dairy sector to bolster farmers’ prosperity and productivity.

Speaking at a press briefing at AgriScot, he said New Zealand dairy farmers are focused on animal welfare and the environment, which in turn has seen the industry reduce the number of ‘bobby calves’ from it’s 4.9m national dairy herd by 400,000 head over the past 3-5 years, through sexed semen.

This had helped to curtail methane emissions and improve margins as more beef sires are used on the remainder of the herd producing calves of an increased value.

However, in contrast to UK milk producers who are often focused on improving milk yields to boost nett margins he said Kiwi farmers are inclined to look to increase milk solids through crossbreeding.

“The Kiwi cross (Holstein Friesian cross Jersey crossbred, or vice-versa) as she is known is the most efficient converter of feed into profit because of the benefits of hybrid vigour and reduced risk of inbreeding.

“Efficient New Zealand dairy farmers look for a 500- 520kg liveweight cow that will produce her bodyweight in milk solids. They want their dairy cows to produce 1kg of milk solids per kg of liveweight and they are targeting sires at or above the national average to get that.

“They also look to breed from cows that are efficient grazers as forage is their main feed source. To them, a ‘greedy cow’ is desirable as she has a large rumen capacity and aggressive grazing behaviour to maximise milk solids.”

By using sexed semen from proven high production bulls in their older, ‘proven’ milk cows in third and even fourth lactations, they are breeding replacement females that are lasting longer.

For example, the NZ average is 4.5 lactations per cow and increasing at 14 days per year. Therefore high cow retention rates are common between years, reducing the need for replacements, whilst boosting the number of available calves for sale.

Mr Bunnett added that Kiwi profit is less to do with the production system, and more to do with management, milk solids production and the costs within the production system.

Similar to the UK, he said there is large variation between milk production and profitability within each herd, with the best looking cow and most productive not necessarily the most profitable female.

“On average there are 160kg of milk solids between the cows in the top quartile and the bottom quartile, so deciding which cows you used sexed semen on can make a huge difference to the future profitability of your herd,” he said.

By concentrating on using the best proven sires instead of unproven high genomic value sires, Mr Bunnett said the heifer calves born would be of a more uniform type and should all be able to kept as replacements instead of focusing on unproven high genomic value sires, which have reduced reliability scores and therefore more risk of breeding a proportion of poorer quality calves, according to joint work done with National Milk Records.

He also encouraged the use of shorter gestation bulls, which produce smaller calves, thereby improving calving ease, future fertility, whilst also reducing the number of lost days in milk.

“You have to make sure you are adding value to the beef calf to be born without sacrificing your milk market,” said Mr Bunnett who added that native sires are more popular down under when the industry relies on grass based feeds.